In one known form of spade drill such as disclosed in the Milton L. Benjamin U.S. Pat. No. 3,966,350 granted June 29, 1976, the beveled and inclined ends at the slotted end of the holder form with the sides and cutting edges of the blade divergent chip passages of obtuse angle cross section which, at the wide ends, open into diametrically opposed obtuse angle longitudinal grooves in the holder. Although the spade drill of said patent has numerous advantages over other known spade drills, the obtuse angle divergent chip passages have a tendency of causing radial outflow of chips into the spaces between the exterior of the holder and the wall of the hole being drilled.